See [1]}, [2]}. This matrix equation can be solved analytically when there are enough symmetries in the problem. For the current plane-strain problem, the three matrices \(Q, R, T\)  have the simple forms
\({ T}=\left(\begin{array}{cc} T_1 & 0 \\ 0 & T_2 \end{array} \right),\;\;\;\;{ R}=\left(\begin{array}{cc} 0 & R_1 \\ R_2 & 0 \end{array} \right),\;\;\;\;{ Q}=\left(\begin{array}{cc} Q_1 & 0 \\ 0 & Q_2 \end{array} \right), \) 
